METHOD AND TREATMENT FACILITY FOR PHYSICAL AND THERMOCHEMICAL TREATMENT OF BIOMASS

Abstract

In a method for physical and thermochemical treatment of biomass, the biomass moisture content is reduced in a dryer and ammonia (NH3) is also released from the biomass during drying. The dried biomass is then either pyrolyzed in a pyrolysis reactor and the pyrolysis gas is forwarded to and combusted in a combustion device to form flue gas, or is combusted in a combustion facility unit to form flue gas. In either case the flue gas is fed to a mixer. Oxygen (O2) is metered to the flue gas in the mixer and is fed directly to the dryer as drying gas. As the drying gas passes through the dryer, the sulfur dioxide (SO2) contained in the drying gas and/or the sulfur trioxide (SO3) chemically reacts with the ammonia (NH3) to form ammonium sulfite ((NH4)2SO3) and/or ammonium sulfate ((NH4)2SO4). Also a treatment facility physically and thermochemically treats the biomass.

Description

Claims

1. A method for the physical and thermochemical treatment of biomass, in particular of organic waste products, such as sludge from sewage treatment plants, slaughterhouses, agricultural operations, animal husbandry, the food industry, the paper industry, in which the following steps are performed in a treatment facility: providing the biomass to be treated,providing a drying device,providing at least one pyrolysis reactor,providing at least one combustion device,providing at least one mixing device,feeding the provided biomass to be treated into the drying device, wherein the moisture contained in the biomass is reduced and ammonia (NH3) is released from the biomass during the drying process,discharging the biomass to be treated from the drying device,feeding the biomass to be treated into the pyrolysis reactor,pyrolyzing the biomass in the pyrolysis reactor and, in the course of this, thermally decomposing the biomass into pyrolysis coke and pyrolysis gas,discharging the pyrolysis coke and discharging the pyrolysis gas from the pyrolysis reactor,feeding the pyrolysis gas discharged from the pyrolysis reactor into the combustion device and combusting the pyrolysis gas thus forming a flue gas,discharging the flue gas from the combustion device and feeding the flue gas into the mixing device,adding oxygen (O2) and or at least an oxygen (O2)-containing gas to the flue gas in the mixing device and forming a drying gas, said drying gas containing, inter alia, sulfur dioxide (SO2) and/or sulfur trioxide (SOs), each in a gaseous aggregate state,discharging the drying gas from the mixing device and feeding the drying gas into the drying device,guiding the drying gas through the drying device, wherein the sulfur dioxide (SO2) and/or the sulfur trioxide (SOs), which is inter alia contained in the drying gas, chemically reacts with the ammonia (NH3) to ammonium sulfite ((NH4)2SO3) and/or ammonium sulfate ((NH4)2SO4).

2. The method according to claim 1, wherein the drying gas is brought to a temperature value in the mixing device, which is in a temperature value range the lower limit of which is 100° C., in particular 300° C., and the upper limit of which is 700° C., in particular 500° C.

3. The method according to claim 1, wherein the drying gas in the mixing device is brought to an oxygen content in an oxygen content value range the lower limit of which is 6 vol%, in particular 15 vol%, and the upper limit of which is 20 vol%, in particular 17 vol%, by adding the oxygen (O2) and/or at least the oxygen (O2)-containing gas.

4. The method according to claim 1, wherein a further flue gas originating from a block-type thermal power station is fed to the mixing device.

5. The method according to claim 4, wherein the further flue gas is fed to the mixing device with a temperature value, which is in a temperature value range the lower limit of which is 100° C., in particular 200° C., and the upper limit of which is 500° C., in particular 300° C.

6. The method according to claim 1, wherein a partial quantity of the flue gas discharged from the combustion device is branched off before being fed into the mixing device, this partial quantity of the flue gas is passed through a heat exchanger and the flue gas temperature is reduced, and subsequently the branched-off flue gas is fed to the combustion device for combustion.

7. The method according to claim 6, wherein ambient air is passed through the heat exchanger as the oxygen (O2)-containing gas and the temperature is raised by means of the flue gas passed through and the ambient air is subsequently fed to the mixing device and metered into the flue gas.

8. The method according to claim 1, wherein the pyrolysis coke discharged from the pyrolysis reactor is fed to a provided coke treatment device and is further decomposed in the coke treatment device into a solid, in particular free-flowing, residue product and into a coke exhaust gas.

9. The method according to claim 8, wherein the residue product is discharged from the coke treatment device being spatially separated from the coke exhaust gas.

10. The method according to claim 8, wherein the coke exhaust gas discharged from the coke treatment device is fed into the combustion device and the coke exhaust gas is combusted in the combustion device thus forming a flue gas and is also discharged therefrom.

11. The method according to claim 8, wherein the pyrolysis gas and the coke exhaust gas are fed into the combustion device separately from one another.

12. The method according to claim 8, wherein the pyrolysis gas and the coke exhaust gas are fed into the combustion device together.

13. The method according to claim 1, wherein the ammonium sulfite ((NH4)2SO3) and/or the ammonium sulfate ((NH4)2SO4) formed in the drying device is or are fed to the pyrolysis reactor together with the dried biomass.

14. A method for the physical and thermochemical treatment of biomass, in particular of organic waste products, such as sludge from sewage treatment plants, slaughterhouses, agricultural operations, animal husbandry, the food industry, the paper industry, in which the following steps are performed in a treatment facility: providing the biomass to be treated,providing a drying device,providing a combustion facility unit with at least one combustion reactor, 19),providing at least one mixing device,feeding the provided biomass to be treated into the drying device, wherein the moisture contained in the biomass is reduced and ammonia (NH3) is released from the biomass during the drying process,discharging the biomass to be treated from the drying device,feeding the biomass to be treated into the at least one combustion reactor (18, 19),combusting the biomass in the at least one combustion reactor and, in the course of this, oxidatively converting the biomass into a combustion product and flue gas,discharging the combustion product and discharging the flue gas from the at least one combustion reactorfeeding the flue gas into the mixing device,adding oxygen (O2) and or at least an oxygen (O2)-containing gas to the flue gas in the mixing device and forming a drying gas, said drying gas containing, inter alia, sulfur dioxide (SO2) and/or sulfur trioxide (SOs), each in a gaseous aggregate state,discharging the drying gas from the mixing device and feeding the drying gas into the drying device,guiding the drying gas through the drying device, wherein the sulfur dioxide (SO2) and/or the sulfur trioxide (SOs), which is inter alia contained in the drying gas, chemically reacts with the ammonia (NH3) to ammonium sulfite ((NH4)2SO3) and/or ammonium sulfate ((NH4)2SO4).

15. The method according to claim 14, wherein the combustion facility unit is formed of multiple combustion reactors (18, 19) and wherein the flue gas in each case formed in these during the combustion is fed to the mixing device.

16. The method according to claim 14, wherein the drying gas is brought to a temperature value in the mixing device, which is in a temperature value range the lower limit of which is 100° C., in particular 300° C., and the upper limit of which is 700° C., in particular 500° C.

17. The method according to claim 14, wherein the drying gas in the mixing device is brought to an oxygen content in an oxygen content value range the lower limit of which is 6 vol%, in particular 15 vol%, and the upper limit of which is 20 vol%, in particular 17 vol%, by adding the oxygen (O2) and/or at least the oxygen (O2)-containing gas.

18. The method according to claim 14, wherein a partial quantity of the flue gas discharged from the combustion facility unit is branched off before being fed into the mixing device, this partial quantity of the flue gas is passed through a heat exchanger and the flue gas temperature is reduced, and subsequently the branched-off flue gas is fed to the combustion facility unit for combustion.

19. The method according to claim 18, wherein ambient air is passed through the heat exchanger as the oxygen (O2)-containing gas and the temperature is raised by means of the flue gas passed through and the ambient air is subsequently fed to the mixing device and metered into the flue gas.

20. The method according to claim 14, wherein the ammonium sulfite ((NH4)2SO3) and/or the ammonium sulfate ((NH4)2SO4) formed in the drying device is or are fed to the combustion facility unit together with the dried biomass.

21. A treatment facility for the physical and thermochemical treatment of biomass, in particular of organic waste products, such as sludge from sewage treatment plants, slaughterhouses, agricultural operations, animal husbandry, the food industry, the paper industry, for performing the method according to claim 14, the treatment facility comprising a drying device, said drying device being configured to reduce the moisture contained in the biomass, and wherein, further, ammonia (NH3) can be released from the biomass during the drying process in the drying device,a combustion facility unit with at least one combustion reactor, said at least one combustion reactor being configured to combust the biomass fed to it, and, in the course of this, oxidatively convert the biomass into a combustion product and flue gas,at least one mixing device, said mixing device being configured to perform an addition of oxygen (O2) and/or at least one oxygen (O2)-containing gas to the flue gas fed to the mixing device from the combustion facility unit to form a drying gas, wherein the drying gas formed by means of the mixing device contains, inter alia, sulfur dioxide (SO2) and/or sulfur trioxide (SOs), each in a gaseous aggregate state,a drying gas supply line, by means of which drying gas supply line the at least one mixing device is in line connection with the drying device, and which is configured to supply the drying gas formed in the mixing device to the drying device.

22. The treatment facility according to claim 21, wherein the combustion facility unit comprises multiple combustion reactors (18, 19) and each one of the combustion reactors (18, 19) is in line connection with the mixing device.

23. The treatment facility according to claim 21, wherein the at least one combustion reactor (18, 19) is selected from the group of a rotary kiln, a fluidized bed furnace, a furnace for carrying out dust firing or cycloid firing, or a furnace with grate firing, such as a stair kiln.

24. The treatment facility according to claim 21, characterized further comprising a block-type thermal power station and a further flue gas originating from the block-type thermal power station can be supplied to the mixing device via a supply line.